Select the correct answer for the following.
1. Complete the word equations for the chemical reactions with the help of choices given in the below.
(Air, iron, baking soda, iron oxide, oxygen, carbon dioxide, iron sulphate, copper, magnesium oxide, lime water, carbon dioxide)
i. + Air + Water → .
ii. Vinegar + → Salt + Water +
iii. Magnesium + →
2. _________ is an essential element for any substance to burn.